author: Christian Brauner <christian.brauner@ubuntu.com> 2021-05-28 11:24:16 +0200
committer: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 2021-07-14 17:06:32 +0200
commit: 2b2a31cad66c129be093474969f860cc0e5553f1
parent: 02d6273ab9bedd8dbd1087080823b0fce9269399
Commit Summary:
Diffstat:
1 file changed, 10 insertions, 3 deletions
diff --git a/fs/open.c b/fs/open.c
index e53af13b5835..53bc0573c0ec 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -1002,12 +1002,20 @@ inline struct open_how build_open_how(int flags, umode_t mode)
inline int build_open_flags(const struct open_how *how, struct open_flags *op)
{
- int flags = how->flags;
+ u64 flags = how->flags;
+ u64 strip = FMODE_NONOTIFY | O_CLOEXEC;
int lookup_flags = 0;
int acc_mode = ACC_MODE(flags);
- /* Must never be set by userspace */
- flags &= ~(FMODE_NONOTIFY | O_CLOEXEC);
+ BUILD_BUG_ON_MSG(upper_32_bits(VALID_OPEN_FLAGS),
+ "struct open_flags doesn't yet handle flags > 32 bits");
+
+ /*
+ * Strip flags that either shouldn't be set by userspace like
+ * FMODE_NONOTIFY or that aren't relevant in determining struct
+ * open_flags like O_CLOEXEC.
+ */
+ flags &= ~strip;
/*
* Older syscalls implicitly clear all of the invalid flags or argument